What is the best course of treatment for a patient with severe asthma exacerbation, recent viral respiratory infection, and a history of steroid use, who has a 90mcg metered dose inhaler (MDI) with spacer?

Treatment of Severe Asthma Exacerbation with 90mcg MDI and Spacer

For a severe asthma exacerbation with a 90mcg MDI and spacer, immediately administer 10-20 puffs (900-1800mcg total) of albuterol via the spacer, which delivers equivalent bronchodilation to nebulized therapy, and simultaneously start oral prednisone 40-60mg daily for 5-10 days without tapering. 1, 2

Immediate Bronchodilator Management

High-dose inhaled beta-agonist therapy is the first-line treatment:

• Administer 10-20 puffs (two puffs repeated 10-20 times) of your 90mcg albuterol MDI into the spacer device immediately 1
• This delivers approximately 900-1800mcg total dose, which is therapeutically equivalent to 5mg nebulized albuterol 1
• Reassess peak expiratory flow and clinical status 15-30 minutes after initial treatment 1, 2

Subsequent bronchodilator dosing depends on initial response:

• If initial response shows <15 percentage point increase in FEV1 at 15 minutes, repeat 6-10 puffs via MDI/spacer every 30 minutes 3
• If initial response shows ≥15 percentage point increase in FEV1, repeat treatments every 60 minutes 3
• Continue frequent treatments until peak flow reaches ≥70% of predicted or personal best 2

Systemic Corticosteroid Therapy

Start oral prednisone immediately—do not delay for any reason:

• Prednisone 40-60mg orally as a single dose or divided into two doses daily 1, 2
• Continue until peak expiratory flow reaches 70% of predicted or personal best 2
• Total course duration: 5-10 days for outpatient management 2
• No tapering is necessary for courses ≤10 days, especially with concurrent inhaled corticosteroids 1, 2

The evidence strongly supports oral over IV administration—oral prednisone has equivalent efficacy to IV methylprednisolone but is less invasive 1, 2. Only switch to IV hydrocortisone 200mg every 6 hours if the patient is vomiting or cannot tolerate oral intake 1, 2.

Severity Assessment and Hospital Referral Criteria

Immediate hospital referral is required if any of the following persist after initial treatment: 1

• Peak expiratory flow <33% of predicted or personal best (life-threatening) 1
• Peak expiratory flow 15-30 minutes after treatment remains <50% of predicted 1
• Respiratory rate >25 breaths/min 1
• Heart rate >110 beats/min 1
• Unable to complete sentences in one breath 1
• Silent chest, cyanosis, or feeble respiratory effort 1

Additional high-risk features warranting lower threshold for admission: 1

• Symptoms seen in afternoon/evening rather than morning 1
• Recent onset of nocturnal symptoms or symptom worsening 1
• History of previous severe attacks, especially with rapid onset 1
• Recent viral respiratory infection (as in this case) 2
• History of steroid use suggesting more severe underlying disease 1

Critical Clinical Algorithm

Step 1 (0 minutes): Administer 10-20 puffs albuterol via MDI/spacer + prednisone 40-60mg orally 1, 2

Step 2 (15-30 minutes): Measure peak flow and reassess 1, 2

• If poor response (<15% improvement): Repeat 6-10 puffs every 30 minutes 3
• If good response (≥15% improvement): Repeat 6-10 puffs every 60 minutes 3
• If life-threatening features present: Call emergency services immediately 1

Step 3 (Ongoing): Continue treatments until peak flow ≥70% predicted 2

Step 4 (Discharge planning): Continue prednisone 40-60mg daily for total 5-10 days 2

Important Clinical Pitfalls to Avoid

Do not underestimate severity by relying on clinical impression alone—always measure peak expiratory flow objectively, as patients and physicians frequently underestimate exacerbation severity 1. This underestimation is a major contributor to asthma mortality 1, 4.

Do not delay systemic corticosteroids—their anti-inflammatory effects take 6-12 hours to manifest, making immediate administration crucial even if initial bronchodilator response appears adequate 2, 4. Delaying steroids leads to poorer outcomes 2.

Do not use inadequate bronchodilator dosing—the MDI/spacer technique requires 10-20 puffs initially to match nebulized therapy effectiveness 1. Single or double puffs are insufficient for severe exacerbations 1.

Do not taper short steroid courses—tapering courses ≤10 days is unnecessary and may lead to underdosing during the critical recovery period 1, 2. Simply stop at full dose after 5-10 days 1, 2.

Do not use arbitrarily short steroid courses—3-day courses are inadequate; evidence supports minimum 5-10 days until clinical control is established 2. Treatment may require up to 21 days if lung function hasn't returned to baseline 1, 2.

Evidence Quality Note

These recommendations are based on high-quality British Thoracic Society guidelines 1, North of England evidence-based guidelines 1, and contemporary expert panel reports 2. The MDI/spacer approach is supported by randomized controlled trials showing equivalent or superior efficacy to nebulization with shorter ED times and lower relapse rates 5.